100 Mr. H. J. Carter on Freshwater Sponges. 
At least this is the result of my examination of several of 
the statoblasts taken from specimens of this sponge which 
Dr. Vejdovsky kindly sent me; but of course I am aware 
that in his illustration (PI.VI. fig. 5) the s¢mple fact of the 
arrangement of the parenchyma around the statoblast in hexa- 
gonal columns perpendicularly to the layer of birotulates on 
the chitinous coat alone is represented. 
As yet I have been able to see this arrangement in frag- 
ments only, partly from the cell-structure being so intricately 
traversed by the skeletal spicules of the species and partly 
from its diffuse extension here and there beyond the surtace of 
the capsule, recalling to mind that which is seen in Spongilla 
fragilis, Leidy=S Lordii, Bk., to which Mr. Potts of Phila- 
delphia directed my attention in the slide of this species which 
he kindly sent me in 1881. 
Being better informed now on the subject than I was when 
I stated that Spongilla erinaceus, Khr., of central Kurope was 
‘identical’ with Meyenia Leidii, Bk., of Pennsylvania in 
North America (‘ Annals,’ 1883, vol. xi. p. 3831), T am now 
able to point out that they are different, viz. that whereas the 
crust in Meyenia Letdit is composed of microcell-structure 
enveloping the layer of birotulates which is fixed to the chiti- 
nous coat and separately surrounded by a capsule of smaller- 
sized spicules than those of the skeleton, although of the same 
form, viz. more or less spined and abruptly pointed, that of 
‘rochospongilla erinaceus is surrounded by the comparatively 
large-cell structure first pointed out by Dr. Vejdovsky (/. ¢.), 
traversed by the long, fusiform, spined, sharp-pointed skeletal 
spicules of the species, as above described. Jn the American 
variety (for we can hardly call the differences specific, although 
it should be considered distinct and still retain its original 
name) the crust is sharply defined and separated from the sur- 
rounding spicular layer, while, as we have seen, in Trocho- 
spongilla erinaceus it is traversed by the skeletal spicules of 
the species which, with their outer points and diffuse cellular 
parenchyma here and there, intermingle with the surrounding 
tissue of the sponge. As I have before stated, however 
(‘ Annals,’ . c. p. 331), the first specimen of Meyenia Letdit 
from the Schuylkill river, kindly sent me on a slide by my 
friend Mr. Potts, bears, in addition to the smaller spicules 
around the statoblast above mentioned, others, viz. skeletal 
ones, almost identical with those of T’rochospongilla erinaceus, 
thus still keeping up the almost endless variety in character 
of the Spongida generally. Other peculiarities of Trocho- 
sponyilla erinaceus are the grey instead of the usual yelk-like 
colour and substance of the germinal contents of the statoblast ; 
